Gear shifting mechanism



Feb. 4, 1941, H. w. HEY

GEAR' SHIFTING MECHANISM 4 Sheets-Sheet 1 'Filed March 15, 1938 HENRY WHEY Feb. 4, 1941. H. w. HEY

GEAR SHIFTING MECHANISM 4 Sheets-Sheet 2 Filed March 15, 1938 H. w. HEY2,230,777

GEAR SHIFTING MECHANISM Fi] .ed l darch 15, 1938 4 Sheets-Sheet 3 \xfkmM Feb. 4, 1941. w H 2,230,777

GEAR SHIFTING MECHANI SM Filed March 15, 1938 4 Sheets-Shet 4 I Z za /6020/ llvm E- MAN/F040 Patented Feb. 4, 1941 UNITED STATES GEAR SHIFTINGNIECHANISM Henry W. Hey, Richmond, Va., assignor to Automatic Shifters,Inc., Richmond, Va., a corporation of Virginia Application March 15,1938, Serial No. 196,083

T 23 Claims.

This invention relates to gear shifting mechanisms.

A number of power operated mechanisms have been developed for shiftingthe gears of motor 5 vehicles most of which employ fluid pressureoperated motors as the source of power. Such motors are adapted to beoperated by being connected through suitable valve mechanisms with asource of fluid under pressure or to the intake l manifold of the motorvehicle engine. Such mechanisms include both the preselective typeswhich permit selection of a gear prior to disengagement of the clutch,and types wherein fol low-up valves are provided for causing theshifting action to take place in accordance with the movement of amanually operated shifting lever.

Gear shifting mechanisms which are fluid pressure operated andcontrolled through the medium ofa follow-up valve mechanism have beenfound to be highly advantageous in operation for several reasons. Forexample, they permit the. gear shifting operations to be carried out inaccordance with conventional practice, thus eliminating the necessityfor the driver learning new 2 modes of operation. Moreover, suchmechanisms permit the floor boards of a vehicle to be cleared to,facilitate the seating of three persons in the front seat and theygreatly minimize the distance through which the operator must move hishand in performing the gear shifting operations.

One of the principal difliculties encountered in the development of gearshifting mechanisms of the type referred to lies in the extremelyvarying conditions under which the gear shifting operations must beperformed. For example, when starting a vehicle in cold weather thetransmission lubricant is highly viscous because of its low temperatureand because it has set" in the transmission casing, and substantialpower is required for performing the shifting operations. Accordingly itis necessary that the shifting motor be of sufllclent capacity toproperly perform the shifting operations under such extreme conditions,when the transmission lubricant offers its maximum resistance to theoperation of the shifting motor. On the other hand, after a motorvehicle has been driven for a few ;minutes, the viscosity' of thetransmission lubricant is greatly reduced either by becoming somewhatheated or by having its viscosity substantially reduced by beingagitated in the transmission by the rotation of the gears therein, orboth. Ac-

as an element opposing operation ofthe shifting 65 motor is verymaterially reduced.

As a result of the substantial differences in the resistances offered tooperation of the shifting motor, the power required for shifting whenthe vehicle motor is cold and the transmission lubricant is set is muchgreater than the power 5 required for performing the shifting operationsafter the transmission lubricant has become warmer or its viscosity hasbeen substantially reduced by agitation. This fact presents asubstantial problem in the development of any motor vehicle gearshifting mechanism, and this is particularly true of mechanisms of thefollowup valve type.

Most transmissions now being manufactured for motor vehicles employ gearsynchronizing means for second and high gears but not for low andreverse gears, it being necessary to efiect sliding movement of a gearinto mesh with another gear when selecting low or reverse gear foroperation. In practice it has been found that if the 0 shift is madeinto low or reverse gear too rapidly or with the application ofexcessive force, the gear being moved sometimes seizes on its shaft andrenders it impossible to move the gear out of mesh for a subsequentshift. Moreover, the 25 same improper shifting causes noisy clashingshifts and excessive wear, and mutilates the gears and dog clutches inthe gear box.- Therefore, it will be apparent that a gear shifting motordesign d to provide the necessary force for shift- 0 ing gears when thevehicle motor is cold and the ,transmission lubricant is highly viscouspossesses far more power than is necessary for performing the shiftingoperations after the transmission lubricant has been heated to someextentor the viscosity of the lubricant has been reduced, and the use ofsuch a motor sometimes results in the seizing of the gears in the mannerdescribed.

Moreover, follow-up valve mechanisms for. shifting mechanisms of thetype referred to are 40 controlled by transmitting movement from amanually operable lever through various mechanical connections such asshafts, rods, linkages, etc., to the valve mechanism and othermechanical connections tend to reverse the valve mechanism in accordancewith the operation ofthe shifting motor or elements operated thereby,

-to provide the necessary follow-up valve action.

Where a shifting motor is over-powered, as when the transmission,lubricant has become warmed, the shifting motor, in an emcient gearshifting. mechanism, tends to over-run its intended position withrelation to the manually controlled lever. In other words, an efiicientfollow-up valve mechanism, used in connection with a shifting motor ofthe necessary size, causes extremely rapid response of the shiftingmotor to movement of the shift lever with the result that the shiftingmotor will operate as rapidly as movement can be transmitted to theshift lever and such rapid movement of the motor sometimes causes it toover-run a position corresponding to the position of the shift leverwhen movement of the latter is stopped.

Accordingly it will be apparent that seizure of the gears may andsometimes does result, and in addition, the extremely rapid operation ofthe motor, acting through its related connection to the follow-up valveand to the shift lever, tends to produce slack in the connectionsbetween the mechanical elements through which motion is transmitted fromthe shift lever to the followup valve. As a result, it is extremelydifficult to provide a quiet operation of mechanical connections betweenthe shift lever and the control valve, such connections tending to causeclicking .and rattling noises.

An important object of the present invention is to provide means forcontrolling the application of power for shifting a transmission inaccordance with conditions existing in the transmission.

A further object is to provide novel means for limiting the generationof power in the shifting motor under normal operating conditions inwhich limited shifting power is required.

A further object is to provide means for controlling the functioning ofa gear shifting motor in accordance with the resistance offered tooperation of the shifting motor, and particularly the resistance offeredto the shifting operations by the transmission lubricant..

A further object is to provide means whereby the operation of theshifting motor will be controlled to provide shifting power which isinversely proportional to the viscosity of the transmission lubricant inorder to provide a uniform shifting operation under all conditions.

A further object is to govern the speed with which the shifting motor ispermitted to respond to operation of the control valve mechanism inaccordance with the temperature conditions in the transmissionlubricant.

A further object is to provide a novel pressure control valve fordetermining the degree of connection of the shifting motor with thesource of pressure fluid independently of the control valve mechanismand depending upon conditions present in the transmission.

A further object is to provide a valve operative for limitingdifferential pressures in the shifting motor by controlling connectionof the shifting motor to a source of non-atmospheric pressure andwherein such valve is biased toward a position providing unlimitedcommunication between the motor and the source, and to provide means forovercoming the biasing means to move the valve toward its seat inaccordance with conditions present in the transmission.

A further object is to provide a control valve of the general characterreferred to which is automatically timed by operation of the vehicleengine to limit differential pressures in the shifting motor duringoperation of the shifting mechanism under normal conditions.

A further object is to provide a spring loaded pressure control valvefor controlling communication between the shifting motor and the sourceof pressure fluid and to provide means for varying the spring loading ofsuch valve in accordance with conditions present in the transmission toprevent any shifting operation from taking place at an excessive rate ofspeed.

A further object is to provide a control valve of the character referredto spring biased to open position and having a differential pressureoperated member operable for urging the valve toward its seat againstthe tension of the spring in accordance with the pressure difierentialconnected to the shifting motor and to provide means for rendering thedifferential pressure operated member inoperative before normaloperating conditions are present in the transmission.

A further object is to provide a valve of the character referred towhich is thermostatically controlled to determine its position andoperation.

A further object is to provide a valve of the character referred towhich is thermostatically controlled in accordance with the temperatureof the transmission lubricant.

A further object. is to provide an automatic control device of thecharacter referred to which is particularly applicable in connectionwith a follow-up valve controlled shifting motor and which functions toeliminate noise in the motion transmitting connections through which thefollow-up valve is operated.

A further object is to provide such a mechanism wherein the movement ofthe shifting motor is caused to lag to a minor extent behind themovement which is manually transmitted to the follow-up valve butwherein such lagging is sufli cient to prevent the motor fromover-running its intended position, thus preventing shifting at anexcessive speed and causing slack to be taken up in the mechanicalconnections through which the follow-up valve is operated to preventnoise from being generated in such connections.

A further object is to provide a mechanism of this character which isparticularly adapted for use in connection with a manually controlledfollow-up valve shifter wherein means is pro-' vided for transmitting"feel to the shift lever,

Other objects and advantages of the invention will become apparentduring the course of the following description.

In the drawings I have shown several embodiments of the invention. Inthis showing:

Figure 1 is a perspective view of the mechanism associated with parts ofa motor vehicle,

Figure 2 is a central vertical longitudinal sectional view through thefollow-up valve mechanism,

Figure 3 is a section on line 33 of Figure 2,

Figure 4 is a vertical sectional view through a control handle mechanismemployed in conjunction with the steering wheel, the latter and thesteering column being shown in elevation,

Figure 5 is a vertical sectional view taken transversely of thetransmission, showing a portion of the casing of the latter and thethermostatically controlled valve associated therewith,

Figure 6 is a face view of the thermostaticall controlled valvemechanism,

Figure '1 is a transverse sectional view of -a portion of the vehicletransmission mechanism taken substantially on line 1-1 of Figure 1,

Figure 8 is a similar view on line 8-8 of Figure 1, I

Figure 9 is a sectional view similar to Figure 5 showing a modified formof the invention,

Figure 10 is a section on line IB-l0 of Figure Figure 11 is a sideelevation of another form of the invention shown attached to the intakemanifold,

Figure 12 is a section on line l2-l2 of F18- ure 11,

Figure 13 is a section on line l9-|l of Figure 11, and,

Figure 14 is a further modification of the invention shown in asectional view similar to Figure 12 and connected to the carburetorchoke 7 operating mechanism. i

Referring to Figures 1, 7 and 8, the numeral l0 designates a motorvehicle transmission provided with a cover plate II, and thetransmission contains the usual gearing fordetermining the driving ratiobetween the vehicle engine and the rear wheels of the vehicle. Thedriving ratio is determinedby the selective shifting of the usual lowand reverse gear shift rail l2 and the second and high gear shift railI3.

In the present construction, means are provided for locking either shiftrail against movement in neutral position andfor applying a forcetending to move both shift rails,- the locking means functioning toprevent movement of one shift rail and thus permit movement of the othershift rail. Referring to Figure 8, the numeral l4 designates a bearingformed in the-cover plate II and receiving a rock shaft l5 provided atone end with a crank l6 whereby it may be rocked between predeterminedpositions in a manner to be described.

The shift rails I2 and I9 are respectively provided with milled groovesH and 18, as shown in Figure 8. These grooves are adapted torespectively receive locking elements 19 and 20 which are verticallymovable in openings 2! and 22 formed in the bottom of the bearing I 4.The shaft i5 is provided with circumferentially offset notches 29 and 24adapted to selectively receive the balls I9 and 20, depending upon theturned position of the shaft I5. It will be apparent that the ballreceiving notches are arranged in the vertical planes of the respectivelocking elements or balls I9 and 29, the shaft i5 being fixed againstlongitudinal movement to maintainit in proper position by a screw 25engageable in a groove 29 formed in the shaft. In this connection, itwill be apparent that the shaft I5 is adapted to project from either endof the bearing i4, depending upon the side of the transmission at whichit is most convenient to operate the crank it, the opposite endof thebearing l4 being-closed by acap 21.

When the shaft occupies the position shown in Figure 8 the lockingmember l9 engages a cylindrical portion of the shaft and thus ismaintained in the groove I! to lock the shift rail l2 against movement.the locking member 29 being freely movable upwardly into the notch 24 topermit the shift rail l3 to be moved longitudinally into either secondor high gear position. Similarlythe crank It may be operated to turn thenotch 23 in'to registration with the locking member l9 and to turn thenotch 24 out of registration with the locking member 2.. Un-

- der such conditions the locking member 29 will tions referred to onlywhen both shift rails are in neutral position, as will become apparent.

Referring to Figures land? it will be noted that the cover plate II isprovided adjacent the bearing II with a preferably larger and longerbearing 29 in which is mounted a rock shaft 29. This shaft projects fromboth ends of the bearing 28 and is provided on one end with an operatingcrank 39. The bearing 29 is formed in two sections the inner ends ofwhich are spaced, and between the bearing sections a hub or sleeve 92 issecured to the shaft 29 and is provided with a depending crank 33 thelower end 34 of which is formed sulmtantially spherical. The lower end34 of the crank engages in an opening 35 formed in a whiiiietree lever36 the ends of which are notched as at 91 to receive the upper ends ofpins 39 and 39 secured to the respective shift rails l2 and l3. 7

In most transmissions it is now the common practice to providesynchronizing means in connection with second and high gears but not inconnection with low and reverse gears; and the latter gear ratios areprovided'by sliding gears into mesh with each other. Accordingly thenecessary distance of travel of the shift rail I2 is greater than thatof the shift rail i3, and for this reason the crank 33 is arranged toone side of the center of the distance between the two shift rails inorder that a given rocking movement of the shaft 29 will move the lowand reverse gear shift rail l2 to a greater extent than the shift raill3 to compensate for the different necessary travels of the shift rails.

A differential fluid pressure motor 49 is employed for rocking the shaft29. This motor comprises a cylinder 4| having a piston 42 thereinprovided with a connecting rod 43 projecting from one end of thecylinder and pivotally conprovided with a pair of spaced heads II and52' and fluid pressure spaces 53 and 54 are defined between these headsand a second pair of heads 55 and 56. A vacuum space 51 is providedbetween the heads 5| and 52.

The valve body 49 is provided in one side thereof with a vacuum passage59 into which is tapped a union 59 connected to one'end of a vacuum pipe69. This pipe leads to the intake manifold as the source of vacuum foroperating the motor 49 through an auxiliary control valve mechanism tobe referred to in detail later. The port. 59 communicates with thevacuum space 5'! to maintain this space in communication with the intakemanifold, and longitudinal movement of the valve 69 is adapted toconnect the vacuum space 51 to either of a pair of ports 8| or 92.

A manifold 99 is secured against the bottom of the valve body 49 asshown in Figures 2 and 3.

This manifold has passages 94 and 69 communicating with the respectiveports 9| and 92.

The passage 64 extends downwardly and rearwardly through an extension 99which is connected to the pipe 46. while the port extends downwardly andlaterally away from the transmission through an extension 61 which isconnected to the pipe 45. Thus it will be apparent that the port 62communicates with the forward or left hand end of the cylinder 4I whilethe port GI communicates with the rear or left hand end of the cylinder4i.

Both of the valve spaces 53 and 54 are in constant communication withthe atmosphere and accordingly movement of the valve 58 in one directionconnects one of the ports GI or 82 to the vacuum space 51 while theother port is connected to the atmosphere through one of the spaces 53or 54. Referring to Figures 2 and 3, the numeral 88 designates amanifold secured against the top of the valve body 48 and provided witha passage 89 communicating through ports 18 and 1| with the respectivevalve spaces 58 and 54. The manifold 68 is provided with a tappedopening 12 to receive the lower end of an air cleaner 13. I

One end of the valve body 48 is provided with an enlarged flange 14having a chamber 15 therein communicating with the port 82 through asmall passage 16. A flexible diaphragm 11 is arranged against the flange14 and a flange 18, similar to the flange 14, is arranged against thediaphragm 11, the two flanges being secured together against oppositefaces of the diaphragm by bolts 19. The flange 18 forms a chamber 88 atthe adjacent side of the diaphragm 11 and this chamber communicates withthe port GI through a passage 8| (Figures 2 and 3). Accordingly it willbe apparent that pressures in the chambers 15 and 88 will be the same atall times as the pressuresin the respective ports 62 and 8|.

The flange 18 carries an axial cylinder 82 in which is slidable a head83, and this head, and the adjacent end of the valve 58, are providedwith flanges 84. These flanges are engaged by the inner offset edges ofdisk members 85 secured against opposite faces of the diaphragm 11. Thisarrangement equalizes the areas of the various parts which arecontrolled by pressures in the chambers 15 and 88 and these pressuresare utilized for providing feel" in the manually operable mechanism tobe described through which the valve 58 is operated.

As stated, a manually operable mechanism is provided for operating thevalve 58 and operation of this valve energizes the motor 48. Movement ofthe piston 42 and the parts operated thereby -is then utilized fortending to reverse the operaopposite end as shown in Figure 1. The otherend of the crank 86 is pivotally connected as at 81 to a floating lever88 intermediate the ends of the latter. The lower end of the lever 88 ispivotally connected as at 89 to a yoke 88 formed on e the forward end ofa link 9|, the rear end of this link being pivotally connected as at 82to the forward end of the valve 58.

The upper end of the floating lever 88 is connected as at 93 to the rearend of a link 94, the connection 98 preferably being in the form of aconventional ball and socket connection to permit free rocking of thetransmission with the vehicle power plant in the resilient mountings.usually provided for this purpose. The forward end of the link 94 has asimilar ball and socket assert? connection 95 with the lower arm 86 of abell crank lever 91 which is pivotally supported intermediate its endsas at 98. The other arm of the bell crank lever is forked or slotted asat 99 whereby the lever 91 may be rocked in a manner to be described tomove the floating lever 88.

The lower end of the crank I8 has connection as at I88-with the rear endof a link IN. The forward end of this link is connected as at I82 withthe lower arm I83 of a bell crank lever I84, this lever being pivotallysupported intermediate its ends as at I88. The other arm I 86 of thelever I84 is provided with a fork I81 the ends of which aresubstantially circular for a purpose to be described.

A' suitable manually operable mechanism for actuating the bell cranklevers 91 and I84 is .shown in Figures 1 and '4. A conventional steeringcolumn I88 is provided at its upper end with the usual steering wheelI89. A supporting collar II8 surrounds and is secured to the steeringcolumn adjacent the upper end thereof and is provided with a laterallyextending portion III forming a bearing for a sleeve I I2. Similarbearing means (not shown) for the lower end of this sleeve also may besecured to the steering column. The lower end of the sleeve II2 carriesa crank arm II3 terminating in a ball II4 receivable in the forks 99,and accordingly it will be apparent that rocking movement of the sleeveI I2 will rock the bell crank lever 91 about its pivot.

An axially movable rod H5 is mounted within the sleeve I I2 and isprovided adjacent its lower end with a pair of disks II6 between whichthe circular members I81 of the bell crank lever I84 are arranged, theforked end of this lever stradtiling the rod II 5.

A sleeve II1 surrounds and is secured to the upper end of the sleeve II2 and has its lower end contacting with the upper face of the bearingII I. At its upper end, the sleeve II1.is provided with a lateralextension II8 which is preferably of inverted U shape in cross sectionand receives the inner end of a manual lever II9, the lever beingpivotally connected to the extension II8 as at I28. The inner end of thelever H9 is provided with a cylindrical opening |2I having an openingI22 in the bottom thereof sufficiently large to permit the rod II5 toextend therethrough, and the rod II! is provided at its upper end with aball I23 arranged in the opening I2I.

The outer end of the lever I I9 is provided with an operating handleindicated as a whole by the numeral I24. This handle is provided with anupper flange portion I25 (Figures 1 and 4) arranged below the outerextremity of the steering wheel and in a plane approximately parallel Ito the plane of the steering wheel. It will be noted that the outer edgeof the flange I25 lies substantially beneath the outer extremity of thesteering wheel I88. Beneath such flange and perpendicular thereto is aflange I28 which extends radially outwardly beyond the flange I25 for apurpose to be described. The handle I24 and associated elements formnopart of the present invention, but are described and claimed in my U.8. Patent No. 2,161,778, issued June 6, 1939.

In Figures 5 and 6 of the drawings there is illustrated a-thermostaticmechanism for controlling communication between the 'vacuum pipe 88 andthe intake manifold. Referring t Figure 5, the numeral I21 designates abulb projecting into the transmission and immersed in the lubricant I28therein. This bulb is carried by aplug I 29 threaded in an opening I38in the side of the transmission casing. The interior of the bulbcommunicates with a preferably sible diaphragm I35 is secured againstthe endwall I33 and communicates with the tube I3I. The bulb I21, tubeI3I and expansible diaphragm I35 are filled with a fluid having a highcoefllcient of expansion as will be apparent. A closure member I36 isprovided for the inner end of the diaphragm I35 and this member isprovided with a closed axially extending portion I31 extending into thediaphragm I35. A plate I38 is secured against the face of the closuremember I36 and is provided with outwardly extending fingers I39engageable in openings I40 in a cup member I4I.

A stem I42 extends freely through the cup member I 4I and is provided atone end with a spring cup I43 receiving one end of a compression springI44 which surrounds the stem I42, the other end of the spring engagingthe cup member MI. The other end of the stem I42 is provided with anintegral disk I45 embedded in a molded elastic valve member I46. Thismember extends radially outwardly in the form of a diaphragm I41 theextremity of which is arranged against a flange I49 formed at the end ofthe casing I34. i

A preferably cast head I49 is arranged against the diaphragm I41 and issecured in position by screws I50 passing through the 'flange I46 asshown in- Figure 5. The head I49 is shown as being provided with acentral recess II surrounded by a valve seat I52 against which the'valve I46 is adapted to seat.

The valve seat I52 is surrounded by an annular recess I54 adapted tocommunicate with the recess I5I in accordance with the position of thevalve I46. The passages I5I and I54 are respectively provided with portsI55 and I56 extending into tapped openings I51 and I58. These openingsare adapted to receive unions I59 and I60, the latter of which isconnected to the pipe 60 as shown in Figure 1. The union I59 isconnected to a pipe I6I leading to the intake manifold.

The valve I46 engages its seat I52 under certain conditions, as willbereferred to in detail later. The loading-of the spring I44 varies inaccordance with the temperature of the lubri cant I28, thus partlydetermining the position of the valve I46, the position of this valvebeing further governed by differential pressures existing on oppositefaces of the valve and its diaphragm portion I41. In this connection itwill be noted that the casing I34 is vented to the atmosphere and forthis purpose the casing has been shown in Figure 5 as having a ventopening I62. The spring I44 is progressively unloaded as the lubricanttemperature increases,

' as will become apparent, and the unloading of the valve mechanism 41.It will be noted that the connection of the tube I9I to the transmissionrequires very little space and this is often advantageous because of thelimited space which is frequently available at such point, particularlyin view of the necessity in some motor cars of mounting the valvemechanism in close proximity to the transmission.

In Figures 9 and a modified form of heat control mechanism has beenshown wherein the entire mechanism is connected to and supported by thetransmission housing. In such form of the invention most of theelements'are identical with the corresponding elements shown in Figure 5and need not be described in detail. Instead of employing the casing I34with its closed end, the fonn of the invention in Figure 9 comprises acasing I64 vented as at I64 and having responding diaphragm I10 whichisopen at its inner end, such end of the expansible diaphragm having acylindrical flange I1'I extending through and secured in the opening inthe flange I66. A bulb I12 is provided at its free edge with a flangeI13 welded or otherwise secured against the innerface of the flange I66.This bulb extends into the transmission through an opening I14 in thetransmission casing and is preferably immersed in the lubricant to beinfluenced by the temperature therein, the bulb I12 and expansiblediaphragm containing a fluid having a high coeflicient of expansion.

As previously stated, the substantial resistance offered to the shiftingmovement when a vehicle engine is cold and the vehicle has been standingfor some time is overcome in either or both of two ways, namely, throughthe heating of the transmission lubricant or through the agitation orbreaking up of the body of the lubricant, for example, by permitting thevehicle engine to warm upfor a few minutes with the clutch enage'd.

In the forms of the invention previously described, the functions of thevarious parts are controlled in accordance with the temperature of thetransmission lubricant, and this lubricant becomes sufficiently warm mevery few minutes by the conduction of heat from the motor and by thegeneration of frictional heat in the body of the lubricant. The devicesare so adjusted that it requires only a few degrees increase intemperature to expand the fluid in the thermostat sufliciently torelease the loading of the spring I44 to permit the valve I46 to assumeits normal position.

Inasmuch-as it is not necessary to depend upon thetemperature of thetransmission lubricant to provide the desired results, the form of theinvention shown in Figuresll, 12 and 13 has been found to beparticularly efficient in operation. The numeral I15 designates a valvebody having a circular recess 116 provided with a port III- adapted tobe connected to the pipe 60 which leads to the valve mechanism 41, thevalve body having a threaded opening I18 to receive a suitable union(not shown) by means of which the pipe 60 may be connected to the valvebody. A passage I19 also is formed in the valve body and past the valveseat I82.

is provided with a threaded opening I to receive a suitable union,whereby the vacuum pipe I8I may be connected to communicate with thepassage I19. An axial passage IBI communicates with the passage I19 andleads through a valve seat I82arranged axially. with respect to therecess I18.

A plate I83 is arranged adjacent and forms, in eifect, a part of thevalve body, as shown in Figure 12. A flexible diaphragm I84 is arrangedbetween the valve body I15 and plate I83, these elements being securedto each other by suitable fastening elements such as screws I85 (Figure13). A valve I88 is carried by the diaphragm I84 and is adapted toregulate the passage of air A compression spring I81 has one endengaging the inner face of the valve I88 and. the opposite end of thisspring is arranged in a cup I88 carried by an adjusting screw I89through which the tension of the spring I81 may be adjusted.

The plate I83 is provided with an opening I90 in which is slidable avalve I9I the upper end of which is engaged by one end of a bi-metallicthermostat I92, the other end of the thermostat being anchored to aprojection I93 formed integral with the plate I88. The valve I9I isprovided with a reduced shank I94 for a purpose to be described.

The plate I83 is provided with a circular recess I95 and the diaphragmI84 is influenced under certain conditions to be described bydifferential pressures in the recesses I18 and I95.

A port I98 is connected between the a valve opening I90 and the recessI95 and is in'constant communication with the space around the valveshank I94. As shown in Figures 12 and 13, a passage I91 connects therecess I18 with the valve opening I90 and when the valve I 9I is in theposition shown in Figure 12, it will be apparent that the passages I98and I 91 afford communication between the diaphragm chambers I95 andI18, and accordingly pressures will be balanced on opposite sides of thediaphragm I84. When the valve I9I is moved downwardly in the manner tobe described, the portion of the valve above the shank I94 will closecommunication between the adiacentends of the passages I98 and I 91 andthe passage I98 will be opened to the atmosphere around the shank I94through-a port I98.

The'valve'mechanism is supported in the desired position in any suitablemanner. In the present instance. the mechanism is shown as beingprovided with a sheet metal or similar casing I99 provided with ears 200secured as at 20I to a part of the intake manifold 202. A part of thecasing I99 extends laterally from the valve mechanism and houses thethermostat I92. and the end of such portion of the housing I 99 is openand arranged adiacent some portion of the motor vehicle en ine to renderthe thermostat sub- .iect to heat generated thereby. In the presentinstance. the end of the casing I99 is shown as being arranged adiacentthe cast pad 203 forming a part of the exhaust manifold and commonly emloyed for controlling the carburetor.

The valve mechanism shown in Figure 14 is identical with the mechanismshown in Figures 11, 12 and 13 except that the valve I 9| is not heatcontrolled. Referring to Figure 14, it will be noted that the valve I9Iextends upwardly through the casing I99 and is pivotally connected atits upper end as at 204 to one end of a bell crank lever 205 pivotallysupported as at 208 to a suitable portion of the carburetor 201. The

pivot 204 may be of any suitable type such as the pin and slotarrangement shown to permit the bell crank lever to swing about itspivot 208. The other arm of the bell crank lever is sim-' ilarlypivotally connected as at 208 with'the carburetor hand choke rod 209which is connected in the usual manner to a crank 2I0 which operates thebutterfly choke valve 2II. This valve is shown in full choking positionunder which conditions the valve I9I will occupy the position shown inFigure 14.

The operation of the form of the invention shown in Figures 1 to 8inclusive is as follows:

Aside from the functioning of the heat control mechanism and its bearingon the shifting mechanism as a whole, the apparatus operates inaccordance with the disclosure in the copending application of John A.Lawler, Serial No. 179,604, filed December 13, 1937. In this connectionit is pointed out that the main valve mechanism 41, the controlmechanism for the valve mechanism, including the manual lever H9 andassociated elements, and the shifting and shift rail locking mechanismsshown in Figures '1 and 8 form no part of the present invention exceptin combination with the mechanisms shown in Figures 5, 6 and 9 to 14inclusive, which function to control other parts of the apparatusdepending upon the resistances encountered by the shifting motor inperforming its intended functions. V Assuming that all of 'the parts ofthe apparatus are in neutral position with the vehicle at rest and it isdesired to start the vehicle in motion; the operator will depress theconventional clutch pedal (not shown), preparatory to shifting into lowgear. This is accomplished by the operator engaging one or two fingersbeneath the flange I25 to lift the lever II9 toward the steering wheel,which action results in selecting the low and reverse gear shift rail I2for operation, followed by engagement of a finger of the operatoragainst the upper or forward face of the flange I28 to move the lever H9rearwardly. In this connection, it is pointed out that a biasing spring,such as the spring I20 shown in Figure 4, tends to hold the free end ofthe lever H9 in the lower position, thus normally selecting the secondand high gear shift rail for operation.

When the operator performs the first of the two movements of the leverII9 referred to. namely, the movement of this lever upwardly toward thesteering wheel, the inner end of the lever II9 will move the stem II5downwardly thus swinging the bell crank lever I04 in a clockwisedirection as viewed in Figure 1. This action transmits a forward pullthrough the link IM to the crank I8 to rock this crank in a clockwisedirection, thus turning the shaft I5- to a position wherein the notch 24is turned out of registration with the locking member 20 and with thenotch 23 arranged directly above the locking member I9. Under suchconditions a cylindrical portion of the shaft I5 will engage the lockingmember 20 to hold it in the groove I8 and thus lock the second and highgear shift rail I3 against movement. At .the same time, the positioningof the notch 23 above the locking member I9 renders such member free tomove upwardly if a force is transmitted to the low and reverse gearshift rail to move the latter longitudinally.

If the operator now pulls the lever II9 rearwardlyto the low gearposition as stated, the sleeve 2 will be rocked in a clockwise directhusproviding a momentarily stationary pivot .81 for the lever 88. Therocking movement of the bell crank lever 91 referred to transmits aforward pull through the link 94 to the upper end of the lever 88, thusturning this lever in a counter-clockwise direction as viewed inFigure 1. Thus the lower end of the lever 98 and consequently the valve59 will be moved rearwardly from the neutral position shown in Figure 2.Under such conditions, the.valve head 52 will move to the right of theposition shown in Figure 2 to connect the port 62 to the vacuum space51, thus exhausting air from the forward or left hand end of thecylinder 4| through the pipe 45. At the same time the valve head 5! alsowill move to the right of its position in Fig-' ure 2, thus connectingthe port 6| to the air space 53 to admit air into the rear or right endof the cylinder 4| through the pipe 16.

Accordingly the piston 42 will start to move forwardly or to the left inFigure 1 to turn the crank 30 and shaft 29in a. clockwise direction.This action rocks the crank 33 toward the operator as viewed in Figure'7 to transmit move ment to the whiffletree lever 36. Inasmuch as thesecond and high gear shift rail will have been locked in the mannerdescribed, thelever 36 will fulcrum on the upper end of the pin 39 andthe opposite end of the lever 36 will transmit movement to the shiftrail 12 to move it toward 10w gear position.

As previously stated the movement manually transmitted to the floatinglever 88 under the conditions being considered moves the rear end ofthis lever rearwardly and upon actuation of the shaft 29 in the mannerreferred to movement of this shaft will be transmitted through the crank86 to the pivot pin 81 to move this element forwardly and thuscounteract rearward movement of the pivot pin 89. The valve 50, havingetieen moved to the right of the position shownin Figure 2 in the mannerdescribed, it will remain approximately in the same position due to thefollow-up action provided through the crank 86 and pivot pin 81. As soonas rearward and downward moyement of the lever H9 is stopped a slightmovement of the piston 42 thereafter will move the pivot pin 61forwardly to a slight extent while the lever 89 fulcrums about the pivot93, thus returning the valve 50 to the normal position shown in Figure2. Thus upon continued'movement of the lever 9 toward low gear positionthere will be continued movement of the motor piston 42 and the partsconnected thereto until low gear position is' reached. Any suitablemeans (not shown) may be provided for limiting movement of the lever H9to each of its operative positions. Accordingly when the low gearposition of the lever H9 is reached, the very slight additional movementof the piston 42 necessary to return the valve 50 to its neutralposition will move the gears completely into low gear. position.

After suiflcient momentum of the vehicle has been attained in low gear,the operator-may disengage the clutch in the usual manner and then movethe lever H9 to second gear position. This may be accomplished byengagement of one fintransmitting elements of the valve 50 will bereversed with relation to their operation when shifting into low gear.In other words, the floating lever 68 will be rocked in a clockwisedirectionto move the valve 60 to the left as viewed in Figure 2, thusopening the port 6| to the vacuum space 67 and. opening the port 62 tothe air space 54.

When neutral position of the lever H9 is reached, further movement ofthis lever parallel to the plane of the steering gear will bemomentarily arrested, whereupon the motor piston 42 will restore thenormal position of the valve 50 and then stop. Without any movement onthe part of the operator the lever H9 will drop downwardly at rightangles to the plane of the steering wheel when neutral position isreached due to the operation of the biasing spring I20 (Figure 4). Thismovement reverses the previously described operation ofthe selectingshaft l5, thus restoring it to the position shown in Figure 8. Undersuch conditions, a cylindrical portion of the shaft l5 will hold thelocking member IS in engagement with the shift rail l2 while the lockingmember 20 will be free to move upwardly into the notch 26 when force isapplied to the shift rail l8.

After the second and high gear shift rail has been selected foroperation in the manner stated, the operator, engaging the flange I26with his finger, may continue to move the lever H9 forwardly andupwardly parallel to the plane of the .ton 42 rearwardly, thustran..nitting force to the whiflietree lever 36. Instead of actuatingthe shift rail l2, however, the lever 36 will fulcrum on the upper endof the pin 38, in view of the locking of the shift rail l2,'and theother end of the lever will transmit movement to the upper end of thepin 39 to movethe shift rail l3 into second gear position.

The vehicle clutch then may be engaged and the vehicle accelerated insecond gear in the usual manner, whereupon the operator may move thelever H9 downwardly and rearwardly parallel to the plane of the steeringwheel N19 to the high gear position. This movement may be accomplishedby engagement of one finger of the operator against the forward or upperface of the flange .l 26 without transmitting movement to the level' H9at right 'angles to the steering wheel. Under such conditions, thesecond and high gear shift rail l3 will remain selected for operationwhile the shift rail l2 will be locked,.and-the valve 50 and associatedparts will operate in accordance with the selection of low gear, thepiston 42 moving from the rear end of the motor 'ner described inconnection with low gear. The lever 9 then may be moved forwardly andupwardly or parallel to the plane of the steering wheel, in which casethe functioning of the shifting mechanism will be the same as for secondgear except that the shift rail I2 will be actuated instead of the shiftrail l3, thus providing reverse gear. As previously stated, all of thesevarious gear shifting operations take place in accordance with thedisclosure of the application of John A. Lawler, Serial No. 179,- 604,referred to above.

The connection of the diaphragm chambers I5 and to the respectivepassages 62 and SI causes the diaphragm chambers to be subjected to thesame pressures as are present in opposite ends of the cylinder 4|. Thusthe differential pressures in the motor 40 will be reproduced onopposite sides of the diaphragm 11 to resist manual operation of thevalve 50 to a degree which is always exactly proportional to theresistance encountered by the piston 42 in its movement. When thispiston is relatively free to move substantial differential pressureswill not be built up on opposite sides of the piston since it tends tomove freely toward the end of the cylinder in which pressure is reduced,thus progressively reducing the volume of such end of the cylinder inproportion to the rate at which air is being exhausted therefrom. Undersuch conditions there will be the same proportionate resistance tomovement of the valve 50.

When the piston 42 encounters resistance, as when disengaging the usualspring detents associated'with the transmission shift rails, or wheninitially engaging the gear synchronizing means of the transmission, themomentary retarding of the piston 42 is immediately followed by afurther reduction in the pressure in the end of the cylinder II which isconnected to the intake manifold, thus building up increaseddifferential pressures to overcome the'resistance encountered by themotor piston. These increased differential pressures are reproduced onopposite sides of the diaphragm Tl, thus offering increased resistanceto the movement of the valve 50 and consequently of the lever I I9.

Thus this lever is provided with feel" which is exactly proportional tothe resistance encountered in the shifting operation. Accordinglyconventional gear shifting is accurately simulated and the operator mayfeel his way into gear inaccordance with conventional practice. Themechanism through which feel is provided performs an additional functioninthat it causes the operator to perform a predetermined proportionateamount of the work in any given shifting operation. It will be apparentthat when the operator moves the lever I IE to move the link 94(Figure 1) to the left, for example, the valve 50 will be moved to theright against the pressure present in the diaphragm chamber 80 (Figure2). Accordingly the operator must move the handle H9 against thedifferential pressure affecting the diaphragm I1, and the force exertedby the hand of the operator is transmitted to the pivot 81 to tend toturn the crank 86 in a clockwise direction. If movement is transmittedtothe link 94 to move it toward the right as viewed in Figure 1, thereverse will be true since differential pressure will tend to move thediaphragm TI toward the right as the operator moves the valve 50 towardthe left. Under such conditions the force of the operator's hand willtend to turn the crank 86 in a counterclockwise direction. Thedifierential pressures affecting the diaphragm 'Il will be the same asthe pressures on opposite sides of the motor piston and will determinethe force which the operator must exert to move the handle 9, andaccordingly the operator will transmit to the crank 86 a manual forcewhich is always in direct proportion to the power generated by the motor40. The features of providing feel" in the manual shift lever and ofcausing the operator to perform a proportional amount of the work ofshifting form no part of the present invention per se but are describedand claimed in my copending application Serial No. 169,288, filedOctober 15, 1937.

As previously stated, an apparatus operated in accordance with thepresent disclosure and without the use of one of the auxiliary valvemechanisms shown in Figures 5 and 6, and 9 to 14 inclusive has beenfound to be highly eflicient in operation. In one sense it may beconsidered that such an apparatus is too eflicient for practicalPurposes. For example, it has been found that the valve mechanism 41 andthe shifting motor 40 are normally so instantaneously responsive tooperation of the lever 9 that the operator may cause the shifts intodifferent gear positions to take place too rapidly, with consequentdisadvantageous results. For example, there is actual shifting of onegear into mesh with another gear when the shift is made into low orreverse andif the shift is made too rapidly or too forcibly, itsometimes occurs that the gear being shifted will seize on its shaft,thus locking the gear set against movement. Moreover, the same impropershifting causes noisy clashing shifts and excessive wear, and mutilatesthe gears and dog clutches in the gear box. This has been found to beparticularly true when shifting into low gear. The present apparatus isso instantaneously responsive to operation of the lever I I9 thatseizing of the gears sometimes occurs.

This condition is aggravated by the fact that the extreme viscosity ofthe transmission lubri cant and the setting thereof when the motor iscold require the provision of a shifting motor of far greater powercapacity than is required during most of the conditions in which gearshifting is accomplished. The maximum degree of viscosity of thetransmission lubricant is present only when the motor vehicle has beensetting for some time and the motor "and transmission are cold, and theviscosity is very' greatly reduced after only a few minutes driving, orafter the vehicle engine has been running a few minutes with the clutchengaged to cause the spinning gears to agitate the lubricant.Accordingly the motor 40 provides far greater power than is necessaryafter the motor and consequently the transmission gears have becomeslightly warmed, or the viscosity of the transmission lubricant has beenreduced by agitation, and the too rapid shifting of the gears causes therelatively highly powered motor '40 to shift gears too rapidly with thedisadvantageous results referred to.

By way of illustration, tests with a'given shifter installationindicated that with' the transmission lubricant at 0 F., a vacuum in theshifting motor of 19 inches of mercury was required to move a shiftrail, and with the particular shifter installation referred to, thisrepresented a force of nearly lb. exerted by the piston-of the shiftingmotor. After several shifts at substantially the same lubricanttemperature, a vacuum of 10 inches of mercury was required with theparticular shifter installation being tested, representing a shiftingmotor piston force of only a little over 65 lb. Accordingly it will beapparent that only approximately 50 per cent. of the force was requiredafter making a few shifts at the same lubricant temperature.

Substantially normal operating conditions are provided after a fewshifts at the same temperature, or after the transmission lubricant hasbecome warmed somewhat to reduce the viscosity of the transmissionlubricant. It has been found that it would be advisable in practice,with the particular installation referred to, to maintain a maximumvacuum of approximately inches of mercury in the shifting motor forshifting under normal conditions. Any substantially greater vacuum hasbeen found to occasionally result in seizing of the gears and inproviding a noisy shifting operation, The lack of means for maintaininga limited degree of vacuum under normal operating conditions has beenone of the highly disadvantageous features of prior transmissionshifting mechanisms. The maximum desirable vacuum will vary in differentshifter installations, of course, depending on shifting motor pistonareas, etc. With reference to the performance of the shifting operationsunder normal transmission conditions, it is well known that some driversmake it a habit to substantially accelerate the speed of a vehicleengine prior to each shift. With the vehicle moving and the motorrunning at a .relatively high speed, the releasing of the throttle formovement to its biased position results in the vacuum in the intakemanifold sometimes rising as high as 25 inches of mercury or more, thevehicle engine acting as a pump under such conditions. It will beobvious that such a degree of vacuum is entirely too high for the propershifting of gears under normal conditionswith a shifting motor which isdesigned to provide the necessary power when maximum resistance to theshifting movement is offered by cold and set transmission lubricant.

It also has been found in practice that regardless of the simplicity ofthe mechanical connections provided between the lever H9 and the valve50' it is extremely difficult to maintain 'a quiet'operation of suchconnections. This also has been found to be due almost entirely to theextremely rapid response of the piston MI to the follow-up valvemechanism, the piston tending to over-run its position under someconditions and tending to provide slack in the connections between thevalve 50 and the lever II9. Accordingly it is highly desirable toprovide a very slight lagging of the piston 42 with respect to the leverII9, under which conditions slack will be taken up in the mechanicalconnections referred to and thus render their operation almostcompletely noiseless,

The mechanisms shown in Figures 5 and 6, and 9 to 14 inclusive overcomethe disadvantagecus' features of operation referred to in that eithertype of control device. is effective in preventing too rapid or .tooforceful shifting of the gears. Moreover, either type of mechanismreferred to functions to eliminate noise from the mechanical connectionsbetween the lever H9 and valve 50.

Referring to Figure 5, it will be noted that the spring IN is preferablyalways loaded and the tension of the spring is adjustable by means ofthe nut which engages the cup Hi3. Assuming that the vehicle is startedwith the motor and transmission cold, the fluid in the Sylphon typethermostat will be relatively contracted and accordingly the cup memberHI will be moved to the right of the position shown in Figure 5, thussubstantially increasing the loading of the spring Md, and moving thevalve M6 further away from its seat. The loading of the spring undersuch conditions will definitely hold the valve I 46 off its seat againstthe action of variable differential pressures on oppositesides of thevalve and its diaphragm, which differential pressures will be referredto later. The degree of communication thus provided between the recessesI5I and I52 will be such that the operation will be the same as if thepipes 60 and'IIiI (Figure 1) were directlyconnected to each other, therebeing no restriction upon the flow of air from the pipe 60 to the pipeI6I beyond the degree of restriction normally inherent in these pipes.

Thus when the apparatus is operated in accordance with the foregoingdescription the shifting motor 40 functions solely in response to theoperation of the valve mechanism 41, the maximum power of the shiftingmotor being available for each shifting operation. This is highlydesirable under the conditions being considered inasmuch as thetransmission lubricant will be highly viscous and will offer substantialresistance to the movement of the motor piston 42 for providing anydesired gear ratio.

It has been found that by conduction of heat from the motor and by thgeneration of frictional heat in the lubricant I28, thislubricantbecomes heated relatively rapidly after the starting of the motor, andaccordingly there is a rapid decrease in the'viscosity of the lubricantshortly after the motor is started, aside from the reduction inviscosity by agitation. As the temperature of the lubricant I28increases, expansion of the thermostat fluid will occur, and thisexpansion moves the free end of the expansible diaphragm toward the leftas viewed in Figure 5 to reduce the loading of the spring I 44.Accordingly, as the temperature of the lubricant progressivelyincreases, there will be a progressive decrease in the force of thespring I acting on the stem I42 to tend to hold the valve I46 off itsseat.

The unloading of the spring occurs progressively until the fingers I39engage the stops I63 at which time the cups MI will be prevented frommoving further to the left as viewed in Figure 5. Accordingly there canbe -no further unloading of the spring beyond such point and the tensionof the spring I is adjusted so as to provide the desired tension whenthe fingers I 39 contact with the stops I63 to thus determine themaximum differential pressure which can be generated in the shiftingmotor.

It will be apparent that when the normal conditions of the engine areestablished, therefore, the position of the valve I 46 will be partlydetermined by the adjusted tension of the spring I44, and the positionof the valve will be further determined by differential pressures onopposite sides of the diaphragm I41 acting in opposition to the springI. The pressure at the right side of the diaphragm as viewed in Figure 5will be constant, namely, the pressure of the atmosphere, while thepressure on the opposite side of the diaphragm will be variable and willbe determined by the speed of operation of the follow-up valve 50.

Movement of the valve 50 will connect one end of the shifting motor tothe intake manifold through the chambers I5I and I54, and since Y oneend of the shifting motor, the rate of exhaustion will depend upon thedegree of vacuum between the shifting motor and the chamber I54, and thefunctioning of the'device in Figure 5 prevents the development of toohigh a degree 7 of vacuum in the chamber I54.

In other words, at any time during the operation of the shifting motorthe valve I46 will be moved against its seat by air pressure acting onthe right hand side of the diaphragm I41 if the pressure in the chamberI54 drops below the point predetermined by the adjustment of the springI44. In this connection it will be noted that the area of the diaphragmI41 is very large compared to the area of the valve I46, thus renderingthe diaphragm properly sensitive to changes in pressure in the chamberI54. If the valve I46 closes during operation of the motor, the buildingup of pressure in the chamber I54 incident to continued exhaustion ofair from the motor cylinder will increase the pressure in the chamberI54, thus reducing the differential pressures affecting the diaphragmI41 and permitting the valve I46 to move off its seat and thus connectthe chambers I5I and I 54 to an extent governed by the distance ofmovement of the valve I46 away from its seat. Upon the reduction inpressure in the chamber I54 incident to the further exhaustion of airtherefrom, it will be apparent that the valve I46 will then move towardits seat and will engage the seat when the pressure in the chamber I54drops to the predetermined point. Thus it will be apparent that thedifferential pressures acting on the diaphragm I41 determine the maximumvacuum which can be established in the chamber I54, and accordinglythemaximum vacuum which can be connected to one end of the shifting motor.In practice it has been'found that a partial vacuum of .approximatelyten inches of mercury in the chamber I54 is satisfactory for providingthe proper maximum speed of operation of the shifting motor. This value,of course, is not a constant for all installations and the proper vacuumfor normal operating conditions can be provided by adjusting the tensionof the spring I44 and thus determine the differential pressures whichwill be required on opposite sides of the diaphragm I41 to seat thevalve I48. Accordingly it will be'apparent that the shifting motor isprevented under all conditions from transmitting excessive force to theshift rails for moving them. Thus a careless or unskilled operator isprevented from shifting gears too rapidly and thus causir he seizin ofthe eers.

The functioning of the device in' the manner stated also causes themovement of the valve 56 to lag slightly. behind the movement of themanual lever II9, although this lagging is not suflicient in actualpractice to be noticeable to the operator or to retard the speed of theshift.- ing operation, unless the operator attempts to shift gears toorapidly. The function of causing the valve 50 to lag behind the leverH9, however, is highly desirable in that it tends to take up all play inthe mechanical connections between the valve 50 and the lever II9, thusrendering such. connections almost entirely a substantial distancetherefrom.

noiseless in operation. As a matter of fact the present invention, fortest purposes, has been deliberately applied to particularly noisymechanisms with the result that noise in the motion transmittingelements referred to has been substantially completely eliminated.

casing I34 .and elements carried thereby to be arranged at any desiredpoint. The device shown in Figure 9 is slightly simpler but possesses adisadvantage in that it is fixed with respect to the transmission casingand projects vehicle constructions are such that there is in- Some motorsuflicient space adjacent the transmission cas- I ing to permit the useof such device, and this is particularly true in installations where itis necessary to mount some other part of the apparatus such as the valvemechanism 41 adjacent the side of the tranmission. However, it will beapparent that the particular mounting of the thermostatic control deviceand the particular form of such device are relatively unimortant. As amatter of fact, it is not essential that the form of thermostat employedinclude a bulb projecting into the transmission since it is fullypracticable to render the apparatus responsive to temperature. changesof the trans mission housing externally thereof.

The form of the device shown in Figures l1, l2 and 13 providessubstantially the same results as in the forms previously described, andhas been found to be especially efiective in actual operation. One ofthe principal advantages of such form of the invention lies in the factthat it does not depend for its operation on the heating of thetransmission lubricant but merely delays the controlling of the shiftingmotor a suflicient length of time to permit the breaking up of thetransmission lubricant either by the spinning of the gears in neutralwith the clutch in engagement or by the accomplishment of the sameresult by the making of several shifts.

Referring to Figure 12, it will be noted that the passage I11 will besuitably connected to the follow-up valve mechanism while the passageI.19 will be connected to the intake manifold. Assuming that the vehicleis at a standstill with the engine idling, preparatory to making ashift, the follow-up valve mechanism will be arranged in neutralposition. Assuming also that the transmission lubricant is cold andrelatively highly viscous and that the vehicle engine has just beenstarted, the thermostat I92 will occupy the solid line position shown inFigure 12, in which case the valve I9I will be in the position shown.Accordingly the atmospheric port I98 will be closed and the space aroundthe valve shank I94 will connect the passages I96 and I91, thusbalancing pressures on opposite sides of the diaphragm I84.

Under such conditions the spring I81, which is loaded to a predeterminedextent by adjusting the screw I89, will be free to exert its full forceagainst the valve I86 to move it to a maximum ential pressure in theshifting motor. Accord-' ingly ample power will be provided for shiftingunder the conditions in which maximum resistance is offered to theshifting movements.

The thermostat I92 is heated by the radiation of heat from the pad 203which forms a part of the exhaust pipe, and it requires relatively fewminutes for sufiicient heat to be generated in the exhaust manifold toextend the thermostat and move it to its dotted line position. When thethermostat moves to such position, it will shift the valve I9I to itsnormal position in which the cylindrical portion of the valve above theshank I94 will disconnect the passage I9I from the passage I96. At thesame time, the space around the shank I94 will connect the passage I96and port I98, thus connecting the diaphragm cham ber I95 to theatmosphere. At the same time, the diaphragm chamber I16, beingdisconnected from the chamber I95, will always have a pressure thereincorresponding to the pressure in the passage IIl.

Accordingly when the normal operation of the mechanism is established,differential pressures will exist on opposite sides of the diaphragmI84, the higher pressure being present in the chamber I95 sincesuchchamber communicates with the atmosphere. The diiferential pressuresaffecting the diaphragm I88, therefore, tend to overcome the tension ofthe spring I8'I to move the valve I86 toward its seat.

Since the pressure in the chamber I95 is constant, the differentialpressures affecting the diaphragm I84 will be directly dependent uponthe pressure in the diaphragm chamber I16. A previously stated, thespring I 81 is loaded to a pre-' determined extent by adjusting thescrew I89, and accordingly any predetermined differential pressureafiecting the diaphragm I84 can be employed for closing the valve I86.In practice it has been found that a vacuum of approximately 10 inchesof mercury in the passage III provides a highly effective operation.Assuming that the spring I8? is adjusted for such a degree of vacuum inthe passage III, it will be apparent that if the valve I86 is arranged aslight distance from its seat I82 to exhaust air from the passage Illand the pressure in such passage drops below the predetermined degree ofvacuum referred to, the differential pressure thus provided on oppositesides of the diaphragm I84 will seat the valve I86 and thus disconnectthe passage I" from the source of vacuum.

Thus it will be apparent that the mechanism, after normal operatingconditions have been established, functions to prevent too high a vacuumfrom being established in the passage I81, and accordingly thedifferential pressures which can be built up in the shifting motor willbe limited to a predetermined vacuum. Thus it will be impossible for anoperator to shift too rapidly by moving the lever H9 at too high a rateof speed. The valve mechanism functions to limit differential pressuresin the shifting motor and thus limit the maximum speed of the shiftingoperation, and the speed of movement of the floating lever 88 by theshifting motor also will be limited. This fact, however, does notprovide a noticeable drag against the operation of the manual lever II'9unless the operator tends tomake a shift too rapidly.

It will be noted that in the form of the invention shown in Figures 11and 12 there is no provention previously described. In actual practicesuch variation in the spring loading is unnecessary, and accordingly thetwo-condition operation of the mechanism in Figure 12 has been found tobe highly efficient. Such mechanism operates in a simple mannertoprovide differ ential pressure in the shifting motor which is limitedonly by the degree of vacuum in the intake manifold when the motor iscold, and it requires only a few minutes time to establish normalconditions in which the resistance offered bythe transmission lubricantis very materially reduced from its maximum. At such time the thermostatI92 functions to move the valve I9I downwardly to its normal position.While there is a progressive downward movement of this valve,

such movement occurs in such a short space oftime that the valve I9Icould be considered as having only two operative positions.

Except for the manner of controlling the valve I9I the form of theinvention shown in Figure 14 is identical in its operation with the formjust described and need not be referred to in detail. Instead ofproviding thermostatic control means for the valve I9I, this valve maybe controlled in accordance with the operation of the carburetor chokevalve. Assuming the device to be associated with an ordinary manualchoke, it will be apparent that when the choke 2 is moved to theoperative position shown in dotted lines in Figure 14, the bell cranklever 205 will be moved to the position shown in'Figure 14, thus placingthe valve I9I in a position corresponding to its position in Figure 12when the motor is cold.

After the vehicle motor has warmed up, the choke will be returned to itsnormal position by v moving the rod 209 to the left to rotate the crank2I8 in a clockwise direction. This action moves the upper arm of thebell crank lever to the left as viewed in Figure 14 and the lower arm ofthe lever will move downwardly to transmit similar movement to the valveI9I and place It in its normal position. Accordingly normal operatingconditions will be established shortly after the vehicle motor has beenstarted. The form of the invention shown in Figure 14 is entirelypracticable but is not preferred for the reason that a vehicle operatorwill occasionally forget to return a hand operated choke to normalposition at the proper time. If the arm 2I0 is thermostatically operatedthe form of the invention shown in Figure 14 will be substantially aspracticable as the form shown in"-'Figure 12.

In view of the foregoing it will be apparent that the present apparatusis of general application in connection with power operated gearshifting mechanisms and that it is particularly advantageous forincreasing the practical efliciency of the follow-up control valvemechanism illustrated. The apparatus controls the functioning of theparts to provide effective shifting regardless of the viscosity of thetransmission lubricant and consequently the resistance offered by thelubricant to the shifting operations. The device effectively preventsseizing of the gears on their shafts due to careless or unskilledshifting, and

the device has the further highly desirable characteristic of silencingthe operation of the mechanical connections between the manual controllever and the control valve mechanism.

It is to be understood that the forms of. the invention herewith shownand described arelto be taken as preferred examples of the same and thatvarious changes in the shape, size and arrangement of parts may beresorted to without departing from the spirit of the invention or thescope of the subjoined claims.

I claim:

1. In combination with a motor actuated shifting mechanism for changingthe driving ratio of a transmission, means for controlling the maximumenergization of said motor, and temperature responsive means forrendering said first named means inoperative.

2. In combination with a motor actuated shit-t ing mechanism forchanging the driving ratio of a transmission, means for controlling themaximum energization of said motor, means for adjusting said last :namedmeans independently of a shifting operation, and temperature responsi-vemeans for rendernig said first named means inoperative.

3. In combination with a motor actuated shifting mechanism for changing.the driving ratio of a transmission, means for controlling energizationof said motor throughout a shifting operation, adjustable means forcontrolling the amount of energy made available to said motorindependently of a shifting operation whereby the force exerted by saidmotor can be adjusted for difierent operating conditions in saidtransmission, andtemperature responsive means for rendering said lastnamed means ineffective for substantially limiting energization of saidmotor.

4. In combination with a motor actuated shifting mechanism for changingthe driving ratio of a transmission, adjustable means for predeterminingthe maximum amount of energy made available to said motor under allconditions whereby the maximum shifting force of said motor will not beexcessive when conditions in the transmission offer minimum resistanceto shifting-operations, and temperature responsive means for determiningthe effectiveness of said last named means.

5. In combination with a transmission and a shifting mechanism forchanging the driving ratio thereof, a difierential fluid pressure motorconnected to actuate said mechanism, means'for limiting the diflerentialfluid pressures to which said motor is subjected, and temperatureresponsive means for determining the effectiveness of said first namedmeans.

6. In combination with a transmission and a shifting mechanism forchanging the driving ratio thereof, a differential fluid pressure motorconnected to actuate said mechanism, means for limiting the difierentialfluid pressures to which said motor is subjected, means for adjustingsaid last named means independently of a shifting operation, andtemperature responsive means for determining the eflectiveness of saidfirst named means.

7. In combination with a transmission and a shifting mechanism forchanging the driving ratio thereof, a differential fluid pressure motorconnected to actuate said mechanism, valve mechanism for controlling theenergization of said motor during shifting operations, adjustable meansoperable independently of said valve mechanism for controlling thediflerential pressuresshifting operations, a manual control member.

connected .to operate said means, adjustable means-independent of saidfirst named means for limiting the energy made available to said motorto prevent the operator from applying excessive shifting force to thetransmission for a particular operating condition thereof, and meansrendered operative during initial operation of the vehicle engine forrendering said last named means ineffective for limiting the energy madeavailable'to said motor.

10; In combination with a motor actuated shifting, mechanism for ashiftable transmission operating member, a manual control member, meansconnected for operation by said member for controlling the energizationof said motor during shifting operations and for supplying a resistanceto manual movements of said control member which is substantiallyproportional to the resistance encountered by said shiftable member,independently adjustable means for limiting the energy made available tosaid motor to prevent the operator from applying excessive force to thetransmission for a particular operating condition thereof, and means forrenderin said last named means ineffective for substantially reducingthe energy made available to said motor.

11. In combination with a motor actuated shifting mechanism for ashiftable transmission operating member, a manual control member, meansconnected for operation by said member for controlling the energizationof said motor during shifting operations and for supplying a resistanceto manual movements of said control member which is substantiallyproportional to the resistance encountered by said shiftable member,independently adjustable means for limiting the energy made available tosaid mdtor to prevent the operator from applying excessive force to thetransmission for a particular operating condition thereof, andtemperature responsive means for at least reducing the effectiveness ofsaid last named means for limiting the energy made available to saidmotor.

12. In combination with a motor actuated shifting mechanism for ashiftable transmission operating member of a motor vehicle, avmanualcontrol member. means connected for operation by said member forcontrolling the energization of said motor during shifting operationsand for supplying a, resistance to manual movements of said controlmember which is substantially proportional to the resistance encounteredby said shiftable member, independently adjustable means for limitingthe energy made available to said motor to prevent the operator fromapplying excessive force to the transmission for a particular operatingcondition thereof, and means rendered inoperative after a period ofinitial operation of the vehicle engine and operative during such periodfor at least limiting the effectiveness of said last named means.

13. In combination with a motor actuated shifting mechanism for ashiftable transmission operating member, a manual controlmember, meansconnected for operation by said member for controlling the energizationof said motor during shifting operations and for supplying a 'resistanceto manual movements of said control member which is substantiallyproportional to the resistance encountered by said shiftable member,auxiliary control means movable to a position limiting the energy madeavailable to said motor, means biasing said auxiliary control meansawayfrom such position, and temperature responsive means movable toprovide a force acting in opposition to said biasing means for movingsaid auxiliary control means to said position.

14. In combination with a motor actuated shifting mechanism for ashiftable transmission operating member of a motor vehicle, a. manualcontrol member, means connected for operation by said member forcontrolling the energization of said motor during shifting operationsand for supplying a resistance to manual movements of said controlmember which is substantially proportional to the resistance encounteredby said shiftable member, auxiliary control means movable to a positionlimiting the energy made avail able to said motor, means biasing saidauxiliary control means away from such position, and means renderedoperative after a period of initial operation of the vehicle engine forproviding a force opposing said biasing means to move said auxiliarycontrol means to said position.

15. The combination with a shifting mechanism for a shiftabletransmission operating member, a difierential fluid pressure motor, amanual control member, valve mechanism, mechanical connections betweensaid valve mechanism and said manual member and said motor to provide afollow-up action of the motor with respect to said manual member,adjustable means for predetermining maximum differential pressures insaid motor independently of said valve mechanism to prevent the operatorfrom applying excessive shifting force to the transmission for aparticular operating condition thereof, and means operative underpredetermined conditions for rendering said adjustable means ineffectivefor substantiallylimiting the application of difnism for a shiftabletransmission operating member, a difierential fluid pressure motor, a.manual control member, valve mechanism, mechanical connections betweensaid valve mechanism and said manual member and-said motor to provide afollow-up action of the motor with respect to said manual member,adjustable means for predetermining maximum difierential pressures insaid motor. independently of said valve mechanism to prevent theoperator from applying excessive shifting force to the transmission fora particular operating condition thereof, and temperature responsivemeans for determining the effectiveness of said adjustable means forcontrolling the application of differential pressures to said motor. v

17, The combination with a shifting mechanism for a shiftabletransmission operating member of a motor vehicle, a differential fluidpressure motor, a manual control member, valve mechanism, mechanicalconnections between said valve mechanism and said manual member and saidmotor to provide a follow-up action of the motor with respect to saidmanual member, adjustable means for predetermining maximum differentialpressures in said motor independently of said valve mechanism to preventthe operator from applying excessive shifting force to the transmissionfor a particular operating condition thereof, and means operative duringa predetermined period of initial operation of the motor vehicle engineunder predetermined conditions for rendering said adjustable meansineffective for substantially limiting the application of differentialpressures to said motor.

18. In combination with a transmission having a shiftable transmissionoperating member, motor means connected to apply a force thereto toshift said member, a manually movable control member accessible to theoperator and connected to control the energization of said motorsubstantially limiting the energy made available Y to said motor. 7

19. In combination with a transmission having a shiftable transmissionoperating member, motor means connected to apply a force thereto toshift said member, a manually movable control member accessible to theoperator and connected to control the energization of said motor means,means applying a smaller and substantially proportional force to saidcontrol member for opposing all movement thereof substantiallysimultaneously with the application of said first mentioned force sothat the operator will feel a resistance to movement of the controlmember substantially proportional to the resistance encountered by saidshiftable member, adjustable means independent of said control memberfor limiting the energy made available to said motor to prevent theoperator from applying excessive shifting force to the transmission fora particular operating condition thereof, and temperature responsivemeans for at least limiting the efl'ectiveness of said adjustable means.

20. In combination with a motor vehicle transmission having a shiftabletransmission operating member, motor meansseonnected to apply a forcethereto to shift said member, a manually movable control memberaccessible to the operator and connected to control the energization ofsaid motor means, means applying a smaller andsubstantially proportionalforce to said control member for opposing all movement thereofsubstantially simultaneously with the application of said firstmentioned force so that the operator will feel a resistance to movementof the control member substantially proportional to the resistanceencountered by said shiftable member, adjustable means independent ofsaid control member for limiting the energy made available to said motorto prevent the operator from applying excessive shifting force to thetransmission for a particular operating condition thereof, and

of initial operation of the vehicle engine for rendering said adjustablemeans ineffective for substantially limiting the energy made availableto said motor.

21. In combination with a differential fluid pressure actuated shittingmechanism for a shittable transmission operating member, a source ofpartial vacuum, control valve mechanism, acouduit connecting said sourceto said valve mechanism, means for operating said valve mechanism tocontrol the connection of said motor to said source and to theatmosphere, a valve seat in said conduit, a valve associated with saidseat, means, biasing said valve away from said seat, diil'erentialpressure actuated means dependent upon the differential betweenatmospheric pressure and pressure in said conduit between said valve andsaid valve mechanism for moving said valve toward said seat against saidbiasing means, and temperature responsive means for rendering saiddifferential pressure actuated means substantially ineffective iormoving said valve against said biasing means.

22. In combination with a differential fluid pressure actuated shiftingmechanism for a shiftable transmission operating member of a motorvehicle, a source of partial vacuum, control valve mechanism, a conduitconnecting said source to said valve mechanism, means for operating saidvalve mechanism to control the connection of said motor to said sourceand to the atmosphere, a valve seat in said conduit, a valve associatedwith said seat, means biasing said valve away from said seat,diflerentiai pressure actuated means dependent upon the diflerentialbetween atmospheric pressure and pressure in said conduit between saidvalve and said valve mechanism for moving said valve toward said seatagainst said biasing means, and means arranged to be operative during aperiod of initial operation of the vehicle engine for rendering saiddiflerential pressure actuated device substantially ineflective iormoving said valve against said biasing means and for rendering saiddiiierential pressure actuated means operative after such period oioperation of the vehicle engine.

23. In combination with a diilerential fluid pressure actuated shiftingmechanism for a shittable transmission operating member, a source ofpartial vacuum, control valve mechanism, a conduit connecting saidsource to said valve mechanism, means for operating said valve mechanismto control the connection of said motor to said source and to theatmosphere, a valve seat in said conduit, a valve associated with saidseat, means biasing said valve away from said seat, a diaphragmconnected to said valve and having opposite faces thereof respectivelysubject to atmospheric pressure and to the pressure in said conduitbetween said valve and said valve mechanism to normally urge said valvetoward its seat against said biasing means, and means for balancingpressures on opposite sides of said diaphragm under predeterminedconditions.

HENRY W. HEY.

